Ocean scientist Paul Butler from Bangor University said: “We got it wrong the first time and maybe we were a bit hasty publishing our findings back then.

“But we are absolutely certain that we’ve got the right age now.

“The nice thing about these shells is that they have distinct annual growth lines, so we can accurately date the shell material.

“That’s just the same as what archaeologists do when they use tree rings in dead wood to work out the dates of old buildings.”

The discovery of Ming was so eye-opening that Help The Aged offered a £40,000 grant to the team to investigate how the molusc, born when Queen Elizabeth I was on the throne, has survived over the centuries.

Before Ming came along, the unofficial record for the world’s oldest animal was held by a 374-year-old Icelandic clam in a German museum.

The clam only grows in summer when the water is warm and it feasts on plankton, each year growing a layer as thin as 0.1 millimetres.